1. Field of the Invention
The invention relates to an improved method and apparatus for detecting bone fragments near the surface of processed meat or fish.
2. Description of the Prior Art
Food products prepared from ground or diced animal flesh, particularly from poultry, cattle, swine, fish, and shellfish, enjoy widespread consumption throughout the United States and the world. However, during the de-bonding or shelling operations in the preparation of these products, bones, bone fragments, and shell fragments may fail to be completely removed from the flesh. Manual detection of these contaminants is not only tedious and costly, but may be subject to human error.
X-ray detection of bones, bone fragments, and shell fragments has been proposed, but this system too is costly, and is not suitable for rapid on-line operations.
Jensen et al. (U.S. Pat. No. 4,631,413) disclosed that bone fragments, fat, cartilage, and connective tissue may be detected in food products by fluorescence. Specifically, the patent disclosed illuminating the product with light having a wavelength of about 325 to 360 nm, and examining the emission of any fluorescence. Emission wavelengths centered at 455 and 475 nm were disclosed as being particularly useful for detection of bones.
However, despite these advances, there exists a continuing need for a high-speed system for detecting bones, bone fragments, and shell fragments in animal flesh with increased sensitivity and accuracy.